Thoracic drainage is normally used to remove gases and air as well as blood or other liquids from the pleural cavity surrounding the lungs. Typically, such drainage is needed after chest surgery, after infliction of a chest wound or injury, after a lung puncture or the like, and in some cases simply to remove excessive amounts of fluids that may accumulate as a result of pneumonia or some other sickness condition.
Such thoracic drainage is carried out either under the influence of gravity or by application of a relatively low vacuum sufficient to avoid the possibility of damage to the patient which might occur if a high vacuum were used. One type drainage system that has been long employed is known as a three bottle system, usually glass bottles, wherein one bottle is utilized to collect the body fluids, a second bottle provides an underwater or liquid seal to prevent backflow of the fluids to the patient, and a third bottle is provided to regulate the amount of vacuum that is applied to the pleural cavity by the system.
Various devices have been developed to replace the breakable glass bottles used in past systems and to combine the functions of two or even three of the bottles of the prior system into a more unitary compact system. Among the more useful of such improvement devices are devices with collection units which combine a collection container together with a liquid seal. To avoid the gradual and sometimes excessive buildup of head pressure and the accompanying increased force developed which may be more than safely required to expel the fluids from the pleural cavity, it is usually desired that the liquid seal be maintained at some limited predetermined depth sufficient to protect against surges caused by coughing or sudden pneumothorax, which might otherwise deplete the liquid seal sufficiently to undesirably allow backflow of fluids, gases, solids and semi-solids to the patient. Generally, in drainage devices useful for both gravity and vacuum systems, the liquid seal is confined to a separate container or chamber usually mounted at a somewhat higher elevation than the larger collection chamber. With such an arrangement, however, the water in the liquid seal is subject to being depleted by tipping or falling over of the drainage unit resulting in the loss of the liquid seal and allowing backflow of undesired substances to the patient. One means of attempting to overcome this problem has been to increase the size (or depth) of the liquid seal chamber and thus the volume of fluids it will accommodate while at the same time maintaining a relatively shallow depth of fluid by means of an overflow means. These expedients have disadvantages and for the most part do not establish a liquid seal which can be readily observed and inspected for bubbling and other conditions which are useful for monitoring the breathing of patients on such devices.
The ability to be able to see into and monitor the bubbling in thoracic drainage devices is highly desirable, and considered important in that the visibility of the bubbling through the water seal enables attending medical personnel to be able to readily monitor and evaluate the strength and condition of the patient's respiratory system. Likewise, the visibility of the lower part of a patient's drainage tube which is the part that is connected to a catheter that communicates with the patient's pleural cavity is extremely important. This is because the extent of the "tidaling" that occurs in such tube affords another means of monitoring the patient's respiration especially for conditions of strength and regularity. Tidaling is the rise and fall of liquids in the patient tube in response to changes in pressure in the pleural cavity. Hence, the visibility of the patient drainage or inlet tube to the present drainage apparatus is an additional highly desirable feature.
Of overriding importance in such thoracic drainage devices is a necessity of preserving the integrity of the underwater or liquid seal against the chance of an accidental tipping or knocking over of the entire drainage apparatus which in known devices can place the patient at risk. This is especially true of prior devices that have relatively small volume liquid seals where even small diminution can allow backflow of gases or liquids to a patient. Such accidental tipping or overturning can readily occur in drainage devices that are suspended from bedrails or other means and where the overturned unit is located below the level of the patient, which is necessary for gravity operation. Knockovers can also occur when drainage units are placed on the floor or other flat surfaces below or alongside the patient's bed. Hence, an underwater or liquid seal must be able to preserve its integrity and function properly even during an accident and when rerighted after such.
Also of extreme importance to such drainage devices is their ability to avoid becoming plugged or blocked especially in any of the communicating fluid and gas passages including those passages in the drainage device itself which might become plugged by blood clots or other solids or semi-solids that are drained from the patient's body cavity. Any plugging which prevents easy airflow is likely to rapidly render breathing very difficult for the patient and puts the patient at risk. Furthermore, blockage of the free fluid flow, if prolonged, will result in the backing up of fluids into the patient's body cavity if not checked and corrected in a very timely manner. Consequently, small size, easily blocked passages for the passage of both fluids and gases are to be avoided whenever possible if the utility of a drainage unit for longterm use such as for several hours or even for days is to be realized.
Accordingly, the present invention is concerned with providing a drainage apparatus, and more particularly, a thoracic drainage apparatus which provides the desirable features of maintaining visibility for monitoring bubbling of gases through the water seal portions, and also for monitoring the tidaling of liquid in the patient tube that needs to be observed for checking the patient's respiration. These conditions need to be monitored in order to know the quality and strength of a patient's respiratory system. The present invention also provides means for overcoming the problem of possible loss of the integrity of the underwater or liquid seal as a result of tipping or overturning of the subject apparatus, and the invention reduces the possibility of potential blockage of the fluid and gas passages. The device also includes means to prevent blockage of the liquid seal chamber and the collection chamber associated therewith due to the undesirable buildup of blood clots or other solid or semi-solid materials passing through such passageways. The present invention therefore represents a substantial improvement over known drainage devices, and overcomes many of the disadvantages and shortcomings of devices used for the same or similar purposes.